Beverage cans of the above type are described, for example, in U.S. Pat. Nos. 4,372,462; 5,011,037; 5,065,882; 5,131,555; 5,129,541; 5,224,618; 5,307,947; 5,375,729; and 5,411,159. Such have been and continue to be widely used in many different settings to consume the beverages by drinking from the cans, often in social gatherings and public places, where the opened can is from time to time rested on a table or bar or the like by the user before being picked up for resuming further drinking from the can.
Beverages served in translucent or transparent glasses can be readily kept track of by indentificable colors or designs, or by colored or marked coasters or tags, or by visual content inspection. While for beverage cans it has been proposed to supply external spring clip identifying tags (U.S. Pat. Nos. 2,976,629 and 5,358,770), coasters (U.S. Pat. No. 2,814,267), cover lids or plates (U.S. Pat. Nos. 3,392,468 and 3,822,496), lid markings for punching as to indicate a date (U.S. Pat. No. 3,201,524), cans as of beer, soda, water, iced tea, juices and other beverages are not easily or inherently identified or distinguished; and, in this present age of very serious and often fatal disease communication through saliva exchange, a user inadvertently picking up and drinking from another's opened can have disastrous consequences.
It is to the provision of a universal, practical, simple, inherent and inexpensive solution of such and related identification problems that the present invention is primarily directed.